Scaffold machine



Feb. 4, 1930. F. B. JOHNSTON I SCAFFOLD MACHINE Filed Jan. 1928 2 Sheets-Sheet l .1 III lll fl anomtoz Feb. 4, 1930. v F. B. JOHNSTON SCAFFOLD MACHINE Filed Jan. 4, 1928 2 Sheets-Sheet 2 Patented Feb. .4, 1930 FRANK: B. JOHNSTON, or Rosanna PARK, NEW JERSEY TATES main P TENT" Price 1 scArroLn Maorrrnn Application filed January 4, 1928. Serial No. 244,426. i

This invention relates to scaffold machines, and more particularly to a device for hoisting and lowering the scaffold platform to the desired position. Y

:5 'It is the primary object and purpose of the present 'inventionto provide a machine or hoisting device of the above character which is adapted tobe suitably mounted upon the I and interlocking therewith.

scafiold beams or putlogs and is characterized principally by the provision of manually o'perable means adapted to coact with a single scaffold suspending chain suitably anchored at its upper end to an outrigger or beam and by thefoperation of which, the scaffold may be readily raised or lowered. In one practical this hoisting and pair of peripherally toothed cog wheels arranged in the same plane and between which the scaffold suspending chain passes, the teeth of said cog wheels each coacting with the chain links from oppositesides of the chain One of these cog wheels is carried by a ratchet wheel adapted to be rotated in'a direction to hoist or raise the scaffold by means of a suitably operated lever and held'against reverse rotation by a 7 spring pressed dog cooperating with the teeth of the ratchet.

"It is also an additional object of the invention-to' provide suitable worm gearing for the purpose of reversing the rotation of said manually operable cog wheel when the ratchet wheel is released whereby the scaffold may be lowered to the desired, position.

fiVVith the above and other'objects in View,

' the invention consists in the'improved scaffold machine, and in the form, construction and relative arrangement of its several parts as will be hereinafter more fully described, illustrated in the accompanying drawings, and subsequently incorporated inthe subjoined claims. I i

In the drawings, wherein I have shown one simple and practical embodiment of the present invention, and in which similar reference characters designate corresponding parts throughout the several views,'

Flgure 1 s a top plan vlew showlng my improved scatfoldmachine, eertain'parts be 7 ing sectioned along the line 1'1 of Fig. 2; Fig. 2 is an edge elevation of the machine; Fig. 3 is a side elevation thereof;

Fig. 4 is a diagrammatic front elevation of part of a building structure showing a scaffold suspended by means of the present in- V building by means of a plurality of open link chains indicated at 6 which are arranged in pairs with the chains in each pair spaced P apart transversely of the platform and positioned adjacent the opposite longitudinal edges of the latter. These chains at their upper ends are connected with the rigidly fixed beams or Outriggers indicated at 7 which project beyond the side of the building.

The platform '5 is composedof' a plurality of planks arranged lengthwise of the scaffold and supported at their ends upon suitable putlogs. As herein shown, each of these putlogs consists of spaced angle beams 8 having their horizontal flanges extending in relatively oppositedirections and connected with eachother adjacent their opposite ends by the vertically disposed U-shaped frame members 9 which are rigidly fixed to said beam flanges at their lower ends as by means of the rivets 10.

Each of the vertically extending arms of each frame9 has a laterally offset upper end portion 11, and is also provided with an oppositely projecting lateral extension 12. The ends of these extensions 12 are angularly bent inwardly towards each other and terminate in the spaced apertured end portions 18 which are adapted to receive the opposite ends of the shaft 14 of a cog wheel 15.

1 A second shaft 16 is also j ournalled in the lower ends of the parts 11 of the frame 9 in horizontal alignment with the shaft 1 .1. and

on said shaft 16 the cog wheel 17 is fixed,

said cog wheel being positioned in the same plane as the wheel15. The cogwheels 15 and 17 are centrally provided upon their peripheral faces with a line of circumferentially spaced radially projecting teeth indicated at 18 and also, between these spaced central teeth with additional radially projecting teeth 19 located adjacent each side face of thecog wheel. The scaffold suspending chain 6 passes between these cog wheels'15 and 17, the central teeth '18 of said cog wheels being adapted for engagement in the openings of the chain links, and the parallel side portions of the links passing through the spaces between There is also fixed upon shaft 16 at one side of'the cog wheel 17 the ratchet wheel 20 having the peripheral teeth 21 adapted for engagementloya spring pressed pawl 22 pivotally mounted as at 23 upon a rod 24 connecting the spaced vertical arms of the frame 9 at their upper ends. 7 V

The outer side face of the ratchet 20 has a plate 25 of relatively small diameter fixed thereto, or this plate may be integrally formed with the ratchet member. Said plate is. provided with equi-distantly spaced transverse openings 26, preferably four in humher, and the outer side face of saidplate spaced from the adjacent vertical arm of the frame 9. In this space one'end of an operating lever 27 is adapted to be inserted, said end of the lever having a fork 28 toremovably embrace the shaft 16. In spaced relation to this fork the lever is provided with a stud 29 projecting from one side thereof and is adapted to looselyfit in one of the openings 26. In spaced relation to this studand on the 'sameside of the lever is formed an angular projection indicated at 30 which is adapted to extend over the periphery of the ratchet wheel 20. Suitably journalled between this angular projection and the lever member, a a pawl 31 is adapted for engagementwith the teeth of the ratchet 20 and is yieldingly held in sliding contact therewith by the leaf spring indicated {It-32. The other end of the lever is provided with a suitably formed handle, and

it will be apparent that when this lever is applied with the lug 29 thereof engaged in one of the openings 26 in plate 25 and the outer end of said lever then lifted with the pawl 31engaged with one of the teeth of the v ratchet, the cog wheel 17 will thereby be positively rotated. ,This cog wheel and the cog wheel 15 being interlocked with oppositevsides of the chain 6, it is apparent that'in the man,- ual operation of the cog wheel 17, the machine will climb or walk upwardly upon the chain 6, thus raising the scaffold 5. The cor're spondin machines, at the opposite edges of the sca old platform should preferably be simultaneously operated. After one opera these central teeth and the side rows of teeth v t-ion of the lever 27, its stud 29 is disengaged: from the opening 26 in the plate 25 and the worm shaft being extended and squared as indicated at 36 for the purpose ofibeing received inthe socket of a suitable crank handle. W'h'enit is desiredto lower the scafl old, the worm may be positioned in operative engagement with the upper side of the worm wheel 33, and for this purpose, I provide the bracket member 35 with a suitably formed groove or channel indicated at 37 to slidably V 7 receive the upper, end of one of the vertical arms of the frame 9. VVhen the worm is properly engaged with the teeth of the worm gear 33, the pawl 22 may then be disengaged from the teeth of the rat'chet20', and said ratchet as well as the cog 17 will be normally lGlCl against anti-clockwise rotation by the resistance of the worm 34. When itais desiredtolower the scaffold, the crank handle is applied to the end of the, worm shaft and the pawl 22 is lifted by hand and heldout of engagement with the teeth of'the ratchet.

The handle is then operated toimpart an anti-clockwise rotation to cog wheel 17 so that the scaffoldstructure will be lowered upon the suspending chain 6. 'Of course,

line Y when the scaffold is to be raised or elevated, I

the bracket members 35carrying-the worms 34 are removed from operative relation to the :i

worm gears 33. The bracket member 35 is held by hand uponthe frame 11 with the worm 34 out of engagement with gear 33f" during the scaffold hoisting or raising -opera-. tion. However, if desired, a I suitable set screwimay be provided to retain the bracket 7 35 and vworm 34 in the inoperative position, a

From the foregoing-"description considered v in connection with theaccompanying drawings, the construction of my "improved scaf fold machine and the manner of-iits application and use will be clearlyunderstood. It will be seen that sucha devicemay be very easily andquickly-arranged in operative position in connection with the scaffold and provides meansleasily operable by the workmen without leaving the scaffold,platform'whereby the scaffold can be either raised or lowered to the desired position with aminimum 'of manual labor. Owing to the interlocking coaction between the pairs of cog wheels 15:

and 17 and the scafiold suspending chains, it

will be evident that there is no possibility of 1 the chains 5 becoming disengaged from the teeth. of said cog wheels so that after adjust-1 I ment of the scaffold, it remains securely locked and held at the in view, but it is apparent that in so far as the mounting and arrangement of the chain engaging dog wheels and operating means therefor is concerned, various alternatlve forms of the described constructlon may be provided. It is likewise apparent that the mechanism itself may be susceptible of more or less modification in the form, proportlon and arrangement of its several 00-' operating elements, and I accordingly reserve the privilege. or resorting to all such legitimate changes therein as may be fairly embodied within the spirit and scope of the invention as claimed.

I claim:

1. In combination with a scaffold and spaced pairs of suspending chains therefor, hoisting machines carried by thescafi'old and cooperating with the respective chains, each machine having a pair of. peripherally toothed cog wheels with their axes arranged in the same horizontal plane and between which the suspending chain extends, the teeth of each cog wheel meshing in the. links of the chain at opposite sides of the latter, and manually operable means for rotating one of the cog wheels in a clockwise direction to thereby efiect an upward movement of the scaffold relative to the chain.

2. In combination with a scaffold platform and a plurality of suspending chains therefor arranged in pairs and anchored at their I one of the cog wheels, a manually operable lever for rotating said ratchet and the cog' upper ends, hoisting machines carried by the scaffold and associated with the respective chains, each of said machines consisting of a pair I of peripherally toothed cog wheels mounted in the same plane for relative rotation, the teethof said cog wheels meshing with the chain links at opposite sides thereof, a ratchet having a fixed connection with per ends, hoisting machines carried by the scaffold and associated with the respective chains, each of said machines consisting of a pair of peripherally toothed cog wheels mounted in the same planefor relative rotation, the teeth of said cog wheels meshing with the chain links, at opposite sides thereof, a ratchet having a fixed connection with one of the cog wheel's, a manually operable leverse direction, a worm gear having a fixed ,ver for rotating said ratchet and the cog wheel in a clockwise direction to move the scaffold upwardly relativetothe chain, a

, locking pawlcoacting with the teeth of the ratchet to prevent rotation thereof in the reconnection with the latter cog wheel, a worm to coact with said worm gear and rotate said cog wheel in an anti-clockwise direction when the pawl is disengaged from said ratchet, and means for removably supporting said worm in cooperative relation with the worm gear.

4. In combination with supporting putlogs for a scaffold platform and scaffold suspendingchains arranged in spaced pairs and anchored at their upper ends, a vertically positioned frame fixed to the opposite end of each putlog, a pair of cog wheels rotatably mounted in said frame in the same plane, each of said cog wheels having a central circumferential row of teeth on its periphery and additional rows of teeth at each side of said central row, the teeth of said cog wheels adapted to mesh with the links of the chain at opposite sides thereof, manually operable means for positively rotating one of said cog wheels in a clockwise direction to move the platform upwardly relative to the chain, and means for releasably locking said cog wheel against rotation in an anti-clockwise direction.

5. In combination with supporting putlogs fora scaffold platform and scaffold suspending' chains arranged in spaced pairs and anchored at their upper ends, a vertically posi- I tioned frame fixed to the opposite ends of each putlog, a pair'of cog wheels rotatably mounted in said frame in the same plane, each of said cog wheels having a central circumferential row of teeth on its periphery and additional rows of teeth at each side of said central row, the teeth of said cog wheels being adapted to mesh with the links of the chain at opposite sides thereof, manually operable means for positively rotating one of said cog wheels in a clockwise direction to move the platform. upwardly relative to the chain,

means for releasably locking said cog wheel against rotation in an anti-clockwise direction, a worm gear having a fixed connection with the latter cog wheel, a worm to coact with said gear and rotate the cog wheel in an anti-clockwise direction to lower the scaffold relative to the chain, and means for removably mounting said worm on the frame in cooperative relation with said worm gear.

6. A scaffold hoisting machine comprising relatively rotatable cog wheels having their axes. positioned in the same horizontal plane,

and the opposed teeth of said cog wheels adapted for engagement with the same link of a scaffold suspending chain extending between said cog wheels, and manually operable means for positively rotating one of said cog wheels.

'7. A soafiol'd hoisting machine comprising relatively rotatable cog Wheels having their axes posltioned in the same horizontal plane, and the opposed teeth of said cog wheels adapted for engagement with the same link of a scaffold suspending chain extending between said cog Wheels, manually operable means for positively rotating one of said 'cog Wheels in one direction'to hoist the scaffold,

m and a separate manually operable means for rotating said cog Wheel in the opposite direction to lower the scaffold.

' In testimony that I- claim the foregoing as my invention,

I have-signed my name hereto.

K B. J OHNSTON'. 

